Implantable cardiac monitors (ICMs) are devices that may be implanted under a patient's skin to continuously monitor the patients cardiac activity. An ICM may be programmed to detect and record cardiac information and episodes such as atrial/ventricular tachycardia, atrial fibrillation, bradycardia, asystole, etc. Triggers for detecting and recording an event (e.g., such a tachy/brady detection rate, a number of events, and/or a duration of asystole) may be programmed by a clinician. Alternatively, when the patient experiences symptoms, the patient may activate the detection and recording using an external patient activator. Diagnostics and recorded events may be downloaded by the clinician in-clinic using a programmer. Further, the data may also be transmitted to the clinician using a daily remote monitoring system.
As compared to external cardiac monitors, ICMs allow clinicians to monitor the patient's cardiac activity for an extended period of time, with an average longevity of up to 36 months. The information recorded by ICMs enables clinicians to determine if a patient complaining of symptoms has irregularities in their heart rhythm that cannot be confirmed in the clinic. The information can also aid the clinician in determining the best course of treatment for the patient (e.g., an addition or change of medication, a procedure such as cardioversion or ablation to restore a regular heart rhythm, and/or implantation of a pacemaker or implantable cardioverter defibrillator for long-term treatment of an irregular heart rhythm).
ICMs are generally relatively small (e.g., 1.1-1.5 cm3 in volume), and can be implanted using a relatively small incision (e.g., 1 cm). Once inserted under the patient's skin, the ICM has a relatively slim profile, mitigating patient concerns about body image. The ICM may be implanted in the patient's chest area near the sternum, and the implant procedure may take less than 10 minutes after application of a local topical anesthesia. Further, ICMs do not deliver pacing or shock therapies to the patient, nor do they require leads to be implanted in the patient's heart.
At least one known method for implanting ICMs includes creating an incision, inserting a tool into the incision and rotating it to create a pocket under this skin, and inserting the ICM using a plunger system that pushes the device in and uses the tool as a guide. However, using at least some known insertion systems, the incision may be relatively difficult to keep open during the procedure. Further, it may be relatively difficult to maneuver the tool into the tissue to position the ICM. For patients with taut tissue, additional force may be required to insert the ICM, while for patients with loose tissue, the ICM may move after implant if a pocket created for the ICM is relatively large. Moreover, in at least some known insertion systems, it may be relatively difficult to push the ICM, which typically has rounded edges, into tissue. Finally, once the ICM is implanted, at least some known insertion systems are relatively difficult to remove from the patient.